The bulk of my question relates to a two-level system, but I have some questions about the Chern number in general as well.
The Chern number of a gapped periodic system (free fermions or mean field) ...

There is a frequently mentioned concept in the field of topological insulator called "bulk-edge correspondence" or "bulk-boundary correspondence", which basically gives the relationship between the ...

in a paper http://arxiv.org/abs/1011.2273 there is a possibility shown that gapped modes at edges can exist for non-trivial interacting topological systems and mathematically shown that gapless modes ...

Majorana mode has attracted great theoretical and experimental interest. The experimental evidence is obtained in quantum wires. The origin theoretical proposals of quantum wires are the papers: 1、R. ...

Polarization is well defined for particle hole symmetry systems, so can we use polarization to identify topological phases? for example polarization can have possible value
$$P=0 \quad or \quad1/2$$
...

This question concerns the very interesting paper: ''Symmetry protected topological (SPT) orders
and the group cohomology of their symmetry group'' by Chen et al., http://arxiv.org/abs/1106.4772
In ...

In the presence of electromagnetic fields $E$ and $B$, four current is not conserved in a Weyl semimetal i.e. $\partial_{\mu} j^{\mu}\propto E\cdot B \neq 0$. There are some proofs in the literature ...

By integrating out fermions in gapped Dirac Hamiltonian, one can obtain a topological term for topological insulator. Why there is no further correction to this term when electron-electron interaction ...

I was reading the paper "Homotopy and quantization in condensed matter physics", by J.E Avron et al. ( http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.51.51). There they have classified the ...

For 2D Time-Reversal Invariant systems ($T H(\vec{k}) T^{-1} = H(-\vec{k}) $), there is a formula by Fu-Kane-Mele in order to determine whether the system belongs to either one of distinct topological ...

The topological property of topological insulators (TIs) is characterized by the non-trivial topological invariants of their band structures, such as $Z_{2}$ topological invariants. While it's clearly ...

Is it correct to write the dispersion relation for following Hamiltonian where $\sigma_{x}$ act in spin space and $\tau_{x}$ acts in pseudo spin particle hole spin
$H_{BdG} (k)=(\xi_{k}+B\sigma_{x}+u ...

I have thought about topological order for a long time, but I am still confused it.
Roughly speaking in my understanding, the topological state is the eigen-state of some special symmetry such time ...

In literatures related to topological insulators, I have frequently encountered the term "time reversal invariant momenta" or TRIM points in the Brillouin zone of the crystal. In many literatures, I ...

As a time reversal protected insulator ($Z_2$ insulator), we can argue that edge states are stable when there exists disorder because time revesal symmetry makes some dynamical matrix elements vanish. ...

How to distinguish between a topological state from from a non-topological one? Is there any standard procedure for identifying the topological features of a given hamiltonian? In general what are the ...

I've been trying to make sense recently of the usage of 'topological' in various fields of physics, and get sort of an intuition for what this means in context. This all boils down to my main question ...